Modern Alpine ski boots are constructed from stiff thermoplastics, and while they facilitate skiing, they are difficult to walk in. The primary reason for this is that the boot sole is flat and inflexible. Those skilled in the art recognize that the problem is solved by attaching a curved oversole or some functionally equivalent device, such as that described by DeFever (U.S. Pat. No. 4,156,316). The ski boot itself can be altered in design to facilitate walking. Annovi (U.S. Pat. No. 4,570,363) and Brugger-Stuker (U.S. Pat. No. 3,971,144) describe boots that have built-in features that increase ease of walking without hindering skiing. The former is a boot with a second sole, and a flexible ankle that can be locked when skiing; the latter is a boot with a curved oversole that is attached at the heel, and can be rotated in and out of position for walking or skiing. This built-in approach may be the the most practical solution to the problem. An attachment such as DeFever's poses an inconvenience to the recreational skier: where to store it while skiing, how to put it on without falling, etc.. The present invention has a unique approach to simplify the composition of a boot that is comfortable to walk in and fully functional to ski in, while requiring no separate attachments or oversoles.